Does exist on the market a differentiator device? Basically connected to a multiway switching to output a pulse of defined length everytime the deviator changes position on/off?
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Discuss Does exist on the market a differentiator device? in the UK Electrical Forum area at ElectriciansForums.net
OP
or better a solid state relay that has a very low control current. The draw back is that accepts only positive dc voltage not negative, so the output should of the circuit should be rectified too.
if V1 is rectified and unipolarity there will need to be a DC path around the capacitor.
It's not now clear to me what supply you have available - AC or DC and at what voltage - and what the nature of the control input is; logic level, a relay coil or what? How far is the switch from the controller? Is it preferable to locate the circuit near the switch or the controller?
Although it is possible to construct a general-purpose circuit that is independent of most of the above parameters, the easiest and smallest implementation will probably benefit from being matched to the specific operational environment.
It's not now clear to me what supply you have available - AC or DC and at what voltage - and what the nature of the control input is; logic level, a relay coil or what? How far is the switch from the controller? Is it preferable to locate the circuit near the switch or the controller?
Although it is possible to construct a general-purpose circuit that is independent of most of the above parameters, the easiest and smallest implementation will probably benefit from being matched to the specific operational environment.
OP
Ok, I explain it better:
The input line at 230Vac (+/-20%) 50Hz is switched on/off, with this signal has to be generated a pulse of time in the range of 0.5 to 2sec to act on a 230Vac load (the gate opener).
Any other voltages needed (i.e. relay coil at 24V) should be taken by voltage step down from 230Vac.
I seek the easiest solution: from market or custom designed.
The 230V control switch can be several meters from the load (gate opener).
Re Lucien’s #14 I have in mind a single-package solution using an LM339 - a=input buffer, b=inverter, a couple of diodes and c + d=window detector.
I had one LM339N quad comparator ic open collector output left over from an earlier project I did. Lucien's idea - or my version of his idea - is attached. It uses one LM339, one npn transistor, two diodes and a few resistors. You can observe the brief pulse off of the left hand LED whenever the SPST dip switch transitions.
Two of the comparators detect input voltage excursions produced by the red spst dip switch at a high threshold of 2/3 Vcc and a low threshold of 1/3Vcc. The third comparator combines/compares the outputs of these two comparators and produces a very brief pulse whenever the input voltage is in the window ie in transition between switch states Viz Vcc 5.5V to 0V Or vice versa. The fourth comparator - a monostable- stretches this very brief pulse to make it visibly wink the left hand LED. The transistor does a signal inversion between the third and fourth comparator because the monostable requires a negative going pulse to trigger it.
I had one LM339N quad comparator ic open collector output left over from an earlier project I did. Lucien's idea - or my version of his idea - is attached. It uses one LM339, one npn transistor, two diodes and a few resistors. You can observe the brief pulse off of the left hand LED whenever the SPST dip switch transitions.
Two of the comparators detect input voltage excursions produced by the red spst dip switch at a high threshold of 2/3 Vcc and a low threshold of 1/3Vcc. The third comparator combines/compares the outputs of these two comparators and produces a very brief pulse whenever the input voltage is in the window ie in transition between switch states Viz Vcc 5.5V to 0V Or vice versa. The fourth comparator - a monostable- stretches this very brief pulse to make it visibly wink the left hand LED. The transistor does a signal inversion between the third and fourth comparator because the monostable requires a negative going pulse to trigger it.
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I understand your requirement is to produce a timed on pulse whenever the switch transitions on to off OR off to on.
To my great shame I have never designed nor constructed or worked on small thermionic valve circuitry. The larger tubes yes. So I will leave the ECC82 technology demonstrator for you to do.
For tireminnanzi - the Italian made bticino gate control system I have worked on only required brief negative going pulses to trigger the controller to do something. Ie. Signal line was normally high at say logic 1 5Volts and when it dipped down to 0Volts ie logic 0 the logic circuits detected this and registered it.
As Lucien has said we really need a much better interface specification from you. References and drawings or sketches would be nice to look at.
Seeing as you've kindly done the quad comparator one, I can't really quibble. TBH the only implementation I would ever get round to doing is the PIC 12F675. I got as far as looking in the drawer but didn't have one. I do have plenty of ECC82s (one of my organs uses 174 of them) but not the time to design and make the coupling transformer.
Of course if it's all going to happen at 230V AC rather than logic level, valves are clearly the way to go. Or I suppose the output could be a little TO-92 triac like a Z01xx but where's the fun in that?
tireminnanzi - good evening Sir.
Is this a search for a solution to one installation‘s problem or for many installations which use the switch you mentioned?
This week I will construct your idea in #15 and report my findings. Are you able to confirm the duration of the pulse and also its waveform. I am being pedantic but the detail matters and could help achieve simplicity and a low component count.
Is this a search for a solution to one installation‘s problem or for many installations which use the switch you mentioned?
This week I will construct your idea in #15 and report my findings. Are you able to confirm the duration of the pulse and also its waveform. I am being pedantic but the detail matters and could help achieve simplicity and a low component count.
By ‘gate opener’ do you mean ‘lock’ for security? Or do you mean servo actuator to open the gate using electrical energy?
OP
Hi Marconi,
the solution should be used in all the installations that require a pulse of some seconds and a button is not available in the producer catalog, only a multiswitch.
For gate opener in this case I intend a sort of electric door opener, it unlock a door, it doesn't control a motor.
Best regards
Building on Tireminnanzi’s idea in #15 here is version 3 using two relays, two diodes and a capacitor to produce a circuit which will momentarily close some no volt contacts whenever a switch is turned off to on and also when next the switch is turned on to off. In my circuit the red spst dip switch bottom right is this switch. Power applied ie switch is on is indicated by the the right hand red LED.
You can hear the no volt contacts closing and opening each time the switch is operated on/off or off/on.
I added in a storage capacitor which is charged up whenever the power is applied ie the switch is on. It is this capacitor which powers the left hand red LED to indicate the momentary closure of the no volt contacts.
So with a 230V ac switch line converted to in my case 12V rectified and smoothed dc - by my power supply box - this circuit will close the no volt contacts for a time determined by one capacitor whenever the switch changes state.
You can hear the no volt contacts closing and opening each time the switch is operated on/off or off/on.
I added in a storage capacitor which is charged up whenever the power is applied ie the switch is on. It is this capacitor which powers the left hand red LED to indicate the momentary closure of the no volt contacts.
So with a 230V ac switch line converted to in my case 12V rectified and smoothed dc - by my power supply box - this circuit will close the no volt contacts for a time determined by one capacitor whenever the switch changes state.
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Ah, the two relay solution. I got as far as two relays lying on the bench. To minimise the power supply requirements, one might want to use 48V relays powered by a capacitive dropper, however in small sizes 48V coils puts the price up significantly. 24V is probably the sensible choice, but I wonder whether the two coils could be wired nominally in series and individually shorted to de-energise? This would halve the dropper current compared to parallel operation.
![[ElectriciansForums.net] Does exist on the market a differentiator device?](https://www.electriciansforums.net/attachments/16291216457646511635461868947053-jpg.88755/ "[ElectriciansForums.net] Does exist on the market a differentiator device?")
A quick gander at electrically operated locks and it seems they generally operate 12 or 24 V some ac, dc or both. In which case they normally have a dedicated power supply connected to the mains and switching and powering the locks are done by 12 to 24V circuits.
Power opened doors and gates I assume can use actuators energised by the mains or lower voltage - my brother in law’s are mains voltage electric motors. Where my friend lives in a secluded controlled access development the gates are 12 or 24 V dc motors IIRC. Signalling for both of these actuators to operate is done at safe voltage levels.
It is not explained by the OP why he is using the mains voltage to signal a lock to be opened. Further it is not clear whether the exact requirements is just to signal a lock to open - it already being supplied with a power supply - or to actual have something between the mains energised on/off switches he mentions and the lock without a power supply to briefly energise them even when the switch transition on to off - Which of course demands energy storage as part of the requirement. I was suggesting this by the storage capacitor added to my version 3 to power the indicator Led for the NVC.
ps (I am assuming a switched line and neutral only).
Power opened doors and gates I assume can use actuators energised by the mains or lower voltage - my brother in law’s are mains voltage electric motors. Where my friend lives in a secluded controlled access development the gates are 12 or 24 V dc motors IIRC. Signalling for both of these actuators to operate is done at safe voltage levels.
It is not explained by the OP why he is using the mains voltage to signal a lock to be opened. Further it is not clear whether the exact requirements is just to signal a lock to open - it already being supplied with a power supply - or to actual have something between the mains energised on/off switches he mentions and the lock without a power supply to briefly energise them even when the switch transition on to off - Which of course demands energy storage as part of the requirement. I was suggesting this by the storage capacitor added to my version 3 to power the indicator Led for the NVC.
ps (I am assuming a switched line and neutral only).
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Tireminannzi: Version 3 functions in a way which I think is close to your switching requirement. Since making it I have had an idea on how to dispense with one of the relays which would reduce the component count. I will have a go at a version 4 tomorrow.
Here is version 4 using only one relay. It takes a switched line and neutral, albeit for safety I use 12Vdc instead of 230Vac, and closes some volt-free contacts briefly every time the switch transitions on/off or off/on.
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